What Is a Brain Teaser? Its Parts, Kinds and What Makes One Good
A brain teaser is a short puzzle with a hidden trap, a moment of insight and one checkable answer. Its kinds, its neighbours and what makes a good one.
Riddle10 blog
Articles about recreational maths
What Is a Number Puzzle? Definition, Kinds and Worked Examples
A number puzzle is a puzzle whose clues and answer are about numbers. Its parts, main kinds, how it differs from an exercise, and what makes a good one.
Chess Board Puzzles: How Many Queens Fit, With and Without Pawns
From eight queens to a quarter of the board: what peer-reviewed papers say about queens, pawns, dragon kings and the distance between squares.
Packing Puzzles: The 70 Square and the Thirty Colour Cubes
Why 24 squares cannot tile a 70 square, how a shorter proof is being built from the edges, and how 30 painted cubes copy each other.
What Is a Puzzle? A Definition From Mathematics and Puzzle Design
A puzzle has a fixed start, fixed rules and a clear goal. What research says makes a puzzle good, what makes it hard, and when it has no solution.
History of Puzzles: Six Classic Puzzles and Where They Came From
A short history of puzzles: eight queens in 1848, the 15-puzzle from the 1870s, the 70 square, coin weighing, truth-tellers and colour cubes.